Open64 cgo07-google 01
- 1. Program Analysis @ Google Robert Hundt, Platforms rhundt@google.com Open64 Workshop, CGO, 3/11/2007
- 2. Challenges Google Applications Typical Profile 6 • Large and complicated 5 • Distributed and irregular 4 • Max out gcc FE space %3 % execution • Well tuned, manually 2 1 Machines 0 1 2 3 4 5 6 7 8 9 10 • Fast evolving Function Program Analysis • Many dimensions • Compiler is an important one • Phase 1: Single machine performance, correctness 2/32 Open64 Tutorial,
- 3. (My) Background Manual Performance Tuning Only vague idea of how compilers work - experimental. Work in Performance Tools Runtime analysis/measurements - no insight into application Work in Compiler Strong static analysis - no runtime information PBO (FDO) improves the situation Many optimizations fail (Almost) no information to the user 3/32 Open64 Tutorial,
- 4. Approach Combine • Static Inter-Procedural Analysis • Runtime Information Create • Advanced Analysis Tools • Performance Tools (Raman, CGO 2007) • Correctness Tools (Engler, Stanford) • High Performance Compiler “Use the compiler as an awkward, but powerful performance analysis tool” 4/32 Open64 Tutorial,
- 5. Strategy Infrastructure: Open64 • Mature, scalable, strong IR, strong research community • LLVM is an option Leverage external • Work with Universities ($) • Leverage cutting edge developments • Push Google specific research • Data Layout Analysis, GVL (Jianian Yan, Paul Yuan) Leverage internal, 20% • Dynamic memory analysis (PIN + static analysis) • Interns (correctness tools) 5/32 Open64 Tutorial,
- 6. Risks Robustness = Critical • Small staff - can’t be eaten by bugs • FE: gcc community • Middle-end: Universities, Osprey, HP, Google • x86 back-end: PathScale, Google • Community effort (!) • Suggestions WELCOME! gcc vs. Open64 vs. LLVM • Clash of civilizations… 6/32 Open64 Tutorial,
- 7. Future A lot of fun ! • Exploring cutting edge developments • Google specific optimizations • Benchmarks soon to be released, please sign up! • Phase 2: Tiered applications • Wild ideas… We are hiring !!! 7/32 Open64 Tutorial,
- 8. Thank You Q/A 8/8 - just kidding Open64 Tutorial,